Templater config syntax update for env vars

* Env vars were not replaced in the templater and is always empty string
  in the rendered yamls.
* Updated the correct syntax for using env in templater

Change-Id: I840d7d246d1408addbe9871e1e251e15a35e0305

manifests/function/airshipctl-base-catalogues/env-vars-template.yaml

@@ -8,6 +8,13 @@ metadata:
     config.kubernetes.io/function: |-
       container:
         image: quay.io/airshipit/templater:latest
+        envs:
+          - HTTP_PROXY
+          - HTTPS_PROXY
+          - http_proxy
+          - https_proxy
+          - NO_PROXY
+          - no_proxy
 template: |
   ---
   apiVersion: airshipit.org/v1alpha1